Vuex3和Vuex4有哪些区别

import Vue from 'vue'
import Vuex from 'vuex'
​
Vue.use(Vuex)
​
const store = new Vuex.Store({
  // 配置项
})
​
export default store

import { createStore } from 'vuex'
​
const store = createStore({
  // 配置项
})
​
export default store

export default {
  computed: {
    count() {
      return this.$store.state.count
    }
  },
  methods: {
    increment() {
      this.$store.commit('increment')
    },
    incrementAsync() {
      this.$store.dispatch('incrementAsync')
    }
  }
}

import { useStore } from 'vuex'
​
export default {
  setup() {
    const store = useStore()
    const count = computed(() => store.state.count)
​
    const increment = () => {
      store.commit('increment')
    }
​
    const incrementAsync = () => {
      store.dispatch('incrementAsync')
    }
​
    return {
      count,
      increment,
      incrementAsync
    }
  }
}

import { mapState, mapGetters, mapMutations, mapActions } from 'vuex'
​
export default {
  computed: {
    ...mapState(['count']),
    ...mapGetters(['doubleCount']),
  },
  methods: {
    ...mapMutations(['increment']),
    ...mapActions(['incrementAsync']),
  }
}

import { computed, useStore } from 'vuex'
​
export default {
  setup() {
    const store = useStore()
​
    const count = computed(() => store.state.count)
    const doubleCount = computed(() => store.getters.doubleCount)
​
    const increment = () => {
      store.commit('increment')
    }
​
    const incrementAsync = () => {
      store.dispatch('incrementAsync')
    }
​
    return {
      count,
      doubleCount,
      increment,
      incrementAsync
    }
  }
}

<template>
  <div>
    <p>Counter 1: {{ counter1 }}</p>
    <p>Counter 2: {{ counter2 }}</p>
    <button @click="incrementCounter1">Increment Counter 1</button>
    <button @click="incrementCounter2">Increment Counter 2</button>
  </div>
</template>
​
<script>
import { useStore } from 'vuex'
​
export default {
  setup() {
    // 使用 useStore 辅助函数创建 Vuex Store 实例
    const store1 = useStore('store1')
    const store2 = useStore('store2')
​
    // 通过 store1.state.count 获取第一个 Store 的状态
    const count1 = store1.state.count
    // 通过 store2.state.count 获取第二个 Store 的状态
    const count2 = store2.state.count
​
    // 通过 store1.commit() 提交 mutations 到第一个 Store
    const incrementCounter1 = () => {
      store1.commit('increment')
    }
​
    // 通过 store2.commit() 提交 mutations 到第二个 Store
    const incrementCounter2 = () => {
      store2.commit('increment')
    }
​
    return {
      count1,
      count2,
      incrementCounter1,
      incrementCounter2
    }
  }
}
</script>